Which netbook do you have which has composite/S-video out over VGA?
I have an Asus netbook (1008HA), and the only thing that comes out of the VGA port is VGA.
If the computer has VGA only, you need a TV/monitor/projector with VGA in, or a scan converter box.
Even if you could get a TV rate RGB, you would need to make a proper chroma carried and lumiance/sync signal. Passively summing the R/G/B signal will not have that.
I have an Asus netbook (1008HA), and the only thing that comes out of the VGA port is VGA.
If the computer has VGA only, you need a TV/monitor/projector with VGA in, or a scan converter box.
Even if you could get a TV rate RGB, you would need to make a proper chroma carried and lumiance/sync signal. Passively summing the R/G/B signal will not have that.